Main. Various other projects exist, one for the connexion of the Danube (near Vienna) with the river Oder at Oderberg, another for a canal from the Danube to the Moldau at Budweis, 125 m. in length, which owing to the regularization of the Moldau is the last uncompleted link of a navigable channel 1875 m. in length between Sulina and Hamburg at the mouths of the Danube and the Elbe respectively. There also exist other schemes for joining the Danube with the rivers Neckar and Theiss, and also for connecting the Oder Canal with the Vistula and the Dniester. Between Ulm and Vienna, a distance of 629 m., works of rectification have been numerous and have greatly improved the navigability of the river. The draining of the Donau-moos between Neuburg and Ingolstadt, commenced in 1791, was successfully completed about 1835; and in 1853 the removal of the rocks which obstructed the river below Grein was finally achieved; while at Vienna itself the whole mass of the Danube was conducted nearer the town for a distance of nearly 2 m. through an artificial channel 10 m. in length and 330 yds. in width, with a depth of about 12 ft., and at a cost with subsidiary works of over three millions sterling. The work, begun in 1866, involved the removal of 12,000,000 cub. metres of sand and gravel, and proved a great success, not only amply realizing its principal object, the protection of Vienna from disastrous inundations, but also improving the navigability of the river in that portion of its course. The Hungarian government also, throughout the latter half of the 19th century, expended vast sums at Budapest for the improvement of navigation and the protection of the town from inundation, and in the regularization of the Danube down to Orsova.
In prehistoric times a great part of the plains of Hungary formed a large inland sea, which ultimately burst its bounds, whereupon the Danube forced its way through the Carpathians at the Kazan defile. Much of what then formed the bottom of this sea consisted until modern times of marshes and waste lands lying in the vicinity of its numerous rivers. The problem of draining and utilizing these lands was not the only difficulty to be surmounted by the Hungarian engineers; the requirements of navigation and the necessity in winter of preventing the formation of large ice-fields, such as caused the disastrous floods at Budapest in 1838, had also to be considered. In carrying out these works the Hungarian government between 1867 and 1895 spent seven millions sterling, and a further expenditure of three and a half millions was provided for up to 1907. At Budapest, where the formation of ice-fields at the upper entrance of the two side arms of the Danube—the Promontor on the north, 20 m. in length, and the Soroksar, 35 m. long,—caused the inundation alluded to, the latter branch has been artificially blocked and the whole of the Danube now flows through Budapest in a single channel. For the first section of 60 m. after entering Hungary, the bed of the river, here surcharged with gravel, was constantly changing its course. It has been regularized throughout, the width of the stream varying from 320 to 400 yds. In the second section from Gönyö to Paks, 164 m. in length, the river had a tendency to form islands and sandbanks—its width now varies uniformly from 455 to 487 yds. The third section of 113 m., from Paks to the mouth of the Drave, differed from the others and made innumerable twists and curves. No fewer than seventeen cuttings have been made, reducing the original course of the river by 75 m. The fourth section, 217 m. in length, from the Drave to Old Moldova, resembles in its characteristics the second section and has been similarly treated. Cuttings have also been made where necessary, and the widths of the channel are 487 yds. to the mouth of the Theiss, 650 between that point and the Save, and lower down 760 yds. In the fifth and last section from Old Moldova to Orsova and the Iron Gates the river is enclosed by mountains and rocky banks, and the obstacles to navigation are rocks and whirlpools.
Article VI. of the treaty of London (1871) authorized the powers which possess the shores of this part of the Danube to come to an understanding with the view of removing these impediments, and to have the right of levying a provisional tax on vessels of every flag which may henceforth benefit thereby until the extinction of the debt contracted for the execution of the works. As the riverain powers could not come to an agreement on the subject, the great powers at the congress of Berlin (1878) entrusted to Austria-Hungary the execution of the works in question. Austria-Hungary subsequently conferred its rights on Hungary, by which country the works were carried out at a cost of about one and a half millions sterling.
The principal obstructions between Old Moldova and Turnu Severin were the Stenka Rapids, the Kozla Dojke Rapids, the Greben section and the Iron Gates. At the first named there was a bank of rocks, some of them dry at low water, extending almost across the river (985 yds. wide). The fall of the river bed is small, but the length of the rapid is 1100 yds. The Kozla Dojke, 9 m. below the Stenka Rapids, extend also for 1100 yds., with a fall of 1 in 1000, where two banks of rocks cause a sudden alternation in the direction of the current. The river is here only 170 to 330 yds. in width. Six miles farther on is the Greben section, the most difficult part of the works of improvement. A spur of the Greben mountains runs out below two shoals where the river suddenly narrows to 300 yds. at low water, but presently widens to 112 m. Seven miles lower down are the Jucz Rapids, where the river-bed has a fall of 1 in 433. At the Iron Gates, 34 m. below the Greben, the Prigrada rocky bank nearly blocked the river at the point where it widens out after leaving the Kazan defile. The general object of the works was to obtain a navigable depth of water at all seasons of 2 metres (6.56 ft.) on that portion of the river above Orsova, and a depth of 3 metres (9.84 ft.) below that town. To effect this at Stenka, Kozla Dojke, Islaz and Tachtalia, channels 66 yds. wide had to be cut in the solid rock to a depth of 6 ft. 6 in. below low water. The point of the Greben spur had to be entirely removed for a distance of 167 yds. back from its original face. Below the Greben point a training wall 7 to 9 ft. high, 10 ft. at top and nearly 4 m. in length, has been built along the Servian shore in order to confine the river in a narrow channel. At Jucz another similar channel had to be cut and a training wall built. At the Iron Gates a channel 80 yds. wide, nearly 2000 yds. in length and 10 ft. deep (in the immediate vicinity of traces of an old Roman canal) had to be cut on the Servian side of the river through solid rock. Training walls have been built on either side of the channel to confine the water so as to raise its level; that on the right bank having a width of 19 ft. 6 in. at top, and serving as a tow-path; that on the left being 13 ft. in width. These training walls are built of stone with flat revetments to protect them against ice. These formidable and expensive works have not altogether realized the expectations that had been formed of them. One most important result, however, has been attained, i.e. vessels can now navigate the Iron Gates at all seasons of the year when the river is not closed by ice, whereas formerly at extreme low water, lasting generally for about three months in the late summer and autumn, through navigation was always at a standstill, and goods had to be landed and transported considerable distances by land. The canal was opened for traffic on the 1st of October 1898. It was designed of sufficient width, as was supposed, for the simultaneous passage of boats in opposite directions; but on account of the great velocity of the current this has been found to be impracticable.
From the Iron Gates down to Braila, which is the highest point to which large sea-going ships ascend the river, there have been no important works of improvement. From Braila to Sulina, a distance of about 100 m., the river falls under the jurisdiction of the European commission of the European commission of the Danube. Danube, an institution of such importance as to merit lengthened notice. It was called into existence under Art. XVI. of the treaty of Paris (1856), and in November of that year a commission was constituted in which Austria, France, Great Britain, Prussia, Russia, Sardinia and Turkey were each represented by one delegate “to designate and cause to be executed the works necessary below Isaktcha[1] to clear the mouths of the Danube as well as the neighbouring parts of the sea, from
- ↑ Isakcea was 66 nautical m. from the sea measured by the Sulina arm of the Danube, 37 m. below Braila and 26 m. below Galatz.
